<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<h1>main</h1>
<p></p>
</body>
<script>
  const electron = require('electron');
  const { ipcRenderer } = electron;

  let count = 0;
  setInterval(() => {
    count++;
    document.querySelector('p').innerHTML = count;
    ipcRenderer.send('update-timer', count);
  }, 1000);
</script>
</html>